A case report of the first application of culture epithelial autograft (JACE®) for giant congenital melanocytic nevus after its approval in Japan

Engineered stem cell-based strategy: A new paradigm of next-generation stem cell product in regenerative medicine

Stem cells have garnered significant attention in regenerative medicine owing to their abilities of multi-directional differentiation and self-renewal. Despite these encouraging results, the market for stem cell products yields limited, which is largely due to the challenges faced to the safety and viability of stem cells in vivo. Besides, the fate of cells re-infusion into the body unknown is also a major obstacle to stem cell therapy. Actually, both the functional protection and the fate tracking of stem cells are essential in tissue homeostasis, repair, and regeneration. Recent studies have utilized cell engineering techniques to modify stem cells for enhancing their treatment efficiency or imparting them with novel biological capabilities, in which advances demonstrate the immense potential of engineered cell therapy. In this review, we proposed that the "engineered stem cells" are expected to represent the next generation of stem cell therapies and reviewed recent progress in this area. We also discussed potential applications of engineered stem cells and highlighted the most common challenges that must be addressed. Overall, this review has important guiding significance for the future design of new paradigms of stem cell products to improve their therapeutic efficacy.

A Case of a Giant Congenital Melanocytic Nevus Treated by Curettage with the Application of Cultured Epidermal Autografts before 6 Months of Age

Curettage is common in the treatment of a giant congenital melanocytic nevus (GCMN) in infants and should generally be performed before 6 months of age. Post-curettage retarded epithelialization often interferes with the ability to perform multiple operations within a short interval, and thus, it is difficult to treat large lesions in the neonatal period. We herein report a case of a GCMN comprising 20% of the total body surface area, which required multi-stage curettage, in which a cultured epithelial autograft was used to promote epithelialization of the post-curettage wound. The patient was a 1-month-old boy with a GCMN in his head, neck, chest, back, buttock, left upper arm, and a few satellite lesions. A four-stage operation was performed between 3 and 6 months of age; the cultured epithelial autograft took well after each operation, and complete epithelialization was observed at postoperative days 20, 23, 27, and 12, respectively. Seven months after the last surgery, hypertrophic scar formation was only observed in a small area of the left upper arm without axillary contracture. The color of the treated area improved, except for slight partial re-pigmentation. A skin biopsy was obtained from the re-pigmented area. The results demonstrated that nevus cells remained in the basal layer of the epidermis, hair follicles, and deep layer of the remaining dermis, suggesting that the recurrent nevus cells in the regenerated epidermis migrated from hair follicles. We conclude that the combination of curettage and the application of a cultured epithelial autograft is a promising option for GCMN treatment.

Cultured epithelial autografts for the treatment of large-to-giant congenital melanocytic nevus in 31 patients

Introduction

Giant congenital melanocytic nevus (GCMN) is a large melanocytic nevus, and its full-thickness removal is usually difficult due to the lack of skin available for reconstruction. Curettage is an alternative approach in cases of GCMN to remove the superficial dermis above the cleavage plane with a curette in the neonatal period, and its major complications include repigmentation, retarded epithelization, and hypertrophic scar formation. In Japan, the JACE® cultured epidermal autograft (CEA) was approved and covered by public healthcare insurance for the treatment of congenital melanocytic nevus (CMN) that is difficult to treat with conventional methods in 2016. We have used CEA for wounds after curettage in the neonatal period or following ablation after the neonatal period in combination with laser therapies to reduce the above-mentioned complications.

Methods

In this study, we summarized all consecutive CMN patients treated using CEA from December 2016 to April 2019 and evaluated the duration required for epithelialization, incidence of hypertrophic scar, and color change in the target nevus by comparing the L∗ values one year later between the Curettage group, the non-Curettage group with initial treatment or the subsequent group.

Results

No significant differences were seen in the epithelization period or incidence of hypertrophic scars among the groups, but the color of the target nevus was improved significantly in the Curettage group (p < 0.01) and non-Curettage group with initial treatment (p < 0.01).

Conclusions

In conclusion, CEA seems to accelerate epithelization after curettage or ablation of CMN, and this treatment could improve the color of CMN when applied initially.

Treatment of giant congenital melanocytic nevi with cultured epithelial autografts: Clinical and histopathological analysis

Introduction

Curettage and dermabrasion are effective in the treatment of giant congenital melanocytic nevi (GCMN); however, local infection and hypertrophic scar formation are major issues. Thus, we applied cultured epithelial autografts (CEA) on skin defects after curettage or abrasion of GCMN and assessed the postoperative outcomes.

Methods

Seven nevi lesions of five patients (aged 3 months to 24 years) were treated with CEA after curettage or abrasion with a dermatome or a surgical bar, respectively. We assessed the postoperative outcomes, including CEA take ratio, erosion and/or ulcer formation in the acute phase, hospitalization days, Vancouver scar scale, and color improvement one year after the operation. In addition, a histological evaluation of a skin biopsy was performed over one year after the operation.

Results

The CEAs took well on the wound, and the wound surface was mostly epithelized by postoperative day 7 in all cases. While hypertrophic scar formation and slight pigmentation were observed in some lesions, the color was improved in all of the treated lesions. Histopathological examination revealed that the regenerated epidermis had stratified keratinocytes with rete ridges, and the dermal layer without nevus cells regenerated above the remaining dermis layer.

Conclusions

In this study, we found that early epithelialization and regeneration of the dermal layer was achieved after the application of CEA, suggesting that CEA could be an effective option after curettage or abrasion of GCMN.

•

Cultured epithelial autograft (CEA) application is effective in the treatment of giant congenital melanocytic nevi.

•

The grafted CEA takes well on skin defects post curettage and abrasion.

•

CEAs can achieve rapid epithelization.

•

Normal dermal tissue regenerates after CEA application.

Clinical Analysis of Cultured Epidermal Autograft (JACE) Transplantation for Giant Congenital Melanocytic Nevus

Background:

Cultured epidermal transplantation (JACE) is performed for giant congenital melanocytic nevus (GCMN), but there are few reports on its postoperative course and surgical content or indications. We aimed to investigate the postoperative course of GCMN patients undergoing cultured epidermal autograft transplantation and compare the outcomes between 2 nevus tissue resection methods.

Methods:

Twelve GCMN patients aged 0 months to 8 years and 9 months were included in this single-center case series study. Cultured epidermal autograft transplantation was performed at 19 sites of the patients’ extremities and trunks, after excision of the nevus either by using an electric dermatome, which we initially used in 2017, or by curettage with a sharp spoon and use of a hydrosurgery system (Versajet), which we started performing in 2018. Univariate and multivariate analyses were performed for factors associated with postoperative hypertrophic scar formation.

Results:

In all cases, >90% of the grafts survived, and the dark brown color of the nevus was reduced. Average postoperative observation period was 16.5 months. Hypertrophic scar formation was observed postoperatively at 9 wound sites out of the 12 sites with GCMN removed with a dermatome and at only 1 site with GCMN removed by curettage with use of a hydrosurgery system. In the univariate and multivariate analyses, hypertrophic scar formation was associated with age at surgery.

Conclusion:

In cultured epidermal autograft transplantation for GCMN, nevus tissue removal at an early age by curettage with use of a hydrosurgery system can provide good results while reducing complications, including recurrence and hypertrophic scar formation.

Effect of Mature Adipocyte-Derived Dedifferentiated Fat Cells on Formation of Basement Membrane after Cultured Epithelial Autograft on Artificial Dermis

BACKGROUND

Artificial dermis is an important option for preparing full-thickness wounds for cultured epithelial autografting. Long-term fragility after cultured epithelial autografting remains a problem, probably because of the lack of basement membrane proteins. The authors hypothesized that treating artificial dermis with mesenchymal stem cells would promote basement membrane protein production. The authors tested this using dedifferentiated fat cells in a porcine experimental model.

METHODS

This study used four male crossbred (Landrace, Large White, and Duroc) swine. Cultured epithelium and dedifferentiated fat cells were prepared from skin and subcutaneous fat tissue harvested from the cervical region. Full-thickness open dorsal wounds were created and treated with artificial dermis to prepare a graft bed for cultured epithelial autograft. Two groups were established: the control group (artificial dermis treated with 0.5 ml of normal saline solution applied to the wounds) and the dedifferentiated fat group (artificial dermis treated with 0.5 × 10 dedifferentiated fat cells suspended in 0.5 ml of normal saline solution sprayed onto the wounds). On postoperative day 10, the prepared cultured epithelium was grafted onto the generated dermis-like tissue. Fourteen days later, tissue specimens were harvested and evaluated histologically.

RESULTS

Light microscopy of hematoxylin and eosin-stained sections revealed the beginning of rete ridge formation in the dedifferentiated fat group. Synthesis of both collagen IV and laminin-5 was significantly enhanced in the dedifferentiated fat group. Transmission electron microscopy revealed a nearly mature basement membrane, including anchoring fibrils in the dedifferentiated fat group.

CONCLUSION

Combined use of artificial dermis and dedifferentiated fat cells promotes post-cultured epithelial autograft production and deposition of basement membrane proteins at the dermal-epidermal junction and basement membrane development, including anchoring fibrils.

Cultured Epidermal Autografts from Clinically Revertant Skin as a Potential Wound Treatment for Recessive Dystrophic Epidermolysis Bullosa

Inherited skin disorders have been reported recently to have sporadic normal-looking areas, where a portion of the keratinocytes have recovered from causative gene mutations (revertant mosaicism). We observed a case of recessive dystrophic epidermolysis bullosa treated with cultured epidermal autografts (CEAs), whose CEA-grafted site remained epithelized for 16 years. We proved that the CEA product and the grafted area included cells with revertant mosaicism. Based on these findings, we conducted an investigator-initiated clinical trial of CEAs from clinically revertant skin for recessive dystrophic epidermolysis bullosa. The donor sites were analyzed by genetic analysis, immunofluorescence, electron microscopy, and quantification of the reverted mRNA with deep sequencing. The primary endpoint was the ulcer epithelization rate per patient at 4 weeks after the last CEA application. Three patients with recessive dystrophic epidermolysis bullosa with 8 ulcers were enrolled, and the epithelization rate for each patient at the primary endpoint was 87.7%, 100%, and 57.0%, respectively. The clinical effects were found to persist for at least 76 weeks after CEA transplantation. One of the three patients had apparent revertant mosaicism in the donor skin and in the post-transplanted area. CEAs from clinically normal skin are a potentially well-tolerated treatment for recessive dystrophic epidermolysis bullosa.

Efficacy of Cultured Epithelial Autograft after Curettage for Giant Melanocytic Nevus of the Head

Supplemental Digital Content is available in the text.

Cultured epithelial autograft (CEA) is an epithelial sheet prepared from a patient’s own skin using cell culture. In Japan, CEA (JACE; Japan Tissue Engineering Co., Ltd., Gamagori, Japan) was approved and covered by public health care insurance for use in the treatment of giant congenital melanocytic nevus (GCMN) in 2016. There are several treatment options for GCMN; however, the complete removal of a GCMN is usually difficult due to the lack of skin. In this report, we describe a case of GCMN in the occipital region that was treated using CEA after curettage. A 2-month-old boy had a GCMN of 13 × 21 cm in his occipital region. We used full-thickness skin taken from the back of the right auricle to prepare CEA under general anesthesia at 4 months of age. Three weeks after preparing CEA, we performed curettage of the right half of the GCMN, and CEA was grafted onto the wound afterward. CEA took completely, and epithelization was observed at 10 days after surgery. We then performed curettage with subsequent grafting of CEA on the left half of the GCMN at 7 months of age. CEA took completely, and epithelization was observed in this procedure as well with no hair loss at 8 months of age. Whether or not curettage can reduce the risk of malignant transformation into malignant melanoma of GCMN is unclear; however, the application of CEA after curettage may be a promising option for obtaining early epithelization.